Abstract: A process for identifying and designating a radially-oriented defect pattern on a data-storage medium comprises determining an angular position of one or more pre-identified defective data sectors on the data-storage medium by counting a number of servo sectors on the data-storage medium that pass a predetermined reference point. The process also comprises defining a radially-oriented pattern of the pre-identified defective data sectors based on a predetermined relationship between: a number of the pre-identified defective data sectors having substantially identical angular positions; and radial spacing between the pre-identified defective data sectors having substantially identical angular positions. The process further comprises writing defect-identification information to data sectors having locations that substantially coincide with the radially-oriented pattern of the pre-identified defective data sectors.

Abstract: A defect map for a data-storage medium is generated without the use of a hard index on the medium. The servo sectors normally written to the medium during formatting operations are utilized to identify the angular positions of defective data sectors. The track-location data typically stored in each data sector is used to identify the radial positions of defective sectors. This positional information is processed by a set of computer-executable instructions that generate a graphical representation of the data-storage medium. Symbols are placed on the graphical representation in positions corresponding to the locations on the medium at which defective data sectors are identified.